I like the idea of a buyback clause, but I don't think it is very common in Italy. I know that Barcelona and Real Madrid do that a lot. Didn't we try to do that with Locatelli when he transferred to Sassuolo (at least that's what rumor suggested)? But the player himself didn't want it (also that's what rumors suggested).

So maybe in the end, the teams have to be attractive enough (Barcelona/RM tier) for the players to even want it.